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Wiring A Car Amplifier
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Wiring an Amplifier

Choose the location for your amplifier. Do not choose to mount it to the box though because vibrations can cause problems with the amp down the road.


Next you are going to need to run wire to your amplifier. Be sure to use the proper gauge wire. Refer to the manual for your amp to find out the proper size

If your battery is top mounted, then you are going to need a ring terminal on the wires to connect to the battery. If this is going into a GM vehicle, then you are going to need to get an extra piece that attaches to the battery because it has side mounted terminals

Figure out how you are going to get the wire from the battery area to where the amp is going to be mounted. In a lot of vehicles there may be a grommet on the passenger side wheel well that is not being used. Or you may find an extra grommet on the drivers side. DO NOT RUN THE WIRE AROUND THE CARS DOOR TO GET THE WIRE INTO THE VEHICLE!!! This is a good way to start a fire!

Begin at the battery. Within 18 inches of the battery, be sure to have some kind of fusing. Use either an ANL fuse, a regular fuse or a circuit breaker. Use the size fuse recommended for your amp. Do not get a bigger fuse than is recommended! Do not put the fuse into the fuse holder yet though. Continue running the wire until you get to where the amp is being mounted. Hiding the wire under the carpeting along the side of the car or running the wire down the center under the center console are the 2 most popular methods. If you plan on running the wire below the vehicle, be sure to house the wire in something to preven the wire from being damaged. And wherever you bring the wire up into the vehicle (usually by drilling a hole in the wheel well) make sure to put a grommet in the hole to keep the wire from being cut by the edges.


Ok now we have the power wire run. Now, to get a signal. You are going to need to run a set of RCA's to the amp location also
For Aftermarket Head Units - run a set of RCA's from where the head unit is at to where the amp will be. If the amp is being used to power a set of mids or highs or both, get the best RCA's you can afford. If the RCA's are for subs then any RCA's is good actually, you are only reproducing bass and so noise is not really an issue. If your RCA's have a thin wire in the middle of the RCA, this is for the remote turn on. If you do not have this wire, you will need to run a wire of about 18 gauge (just ask for remote turn on wire) from the head unit location to the location where the amp will be at.

Now connect the RCA to the proper place on the head unit and connect the remote turn on wire to the remote wire coming out of the wire harness of the head unit. It will either be blue or blue with a white stripe

For OEM head units - you are going to need to get a Line Out Converter. This is a box that will let you splice into your rear speaker and it will take the speaker level output voltage and drop it to a lower level and will allow you to connect a set of RCA's to it that you will now be able to run to your amplifier

Be sure when running RCA's that you do not run them next to the power wire you just ran


You are going to need to locate a good area to ground your amp to. The chassis is always ideal but a good piece of double stamped metal will also work. Another option is locating a screw in the vehicle that is screwed into the chassis. Just remove the screw and put the ring terminal on the ground wire under it and screw it back down. Make sure you scrape any paint off of the metal first though. It should be bare metal that is nice and shiny for a good connection. Now run this wire to the amplifier location also.

Wiring an Amplifier To Speakers


Hopefully by now you know if you are wiring subs or components and will also know if your amp is 2 channels or 4 channels so I am not going to get into that. For subs, run your speaker wires to the amp from the location of where the subs are located at. For OEM replacements, it is probably easiest to just run speaker wires from where the amp will be located to the head unit and then just connect the speaker wires you just ran to the speaker wires on the harness to their corresponding locations. For speakers that have been relocated or for speakers that you are running new wire to, run the speaker wire from the amp to the location of the speaker. Whichever situation you have, make sure to remember to make not of positive or negative somehow it the wire is not labeled. I know that Stinger wire has one wire in square insulation and the other wire in round insulation. And Monster cable has writing on one of the wires only. So make a note of this

The wire that you ran from the battery will get connected on the amp on the terminal that is either marked "+" or "POS" and the wire that came from ground will get connected to the terminal marked "-" or "GND" or "NEG" and the remote wire will get connected to the terminal marked "REM". You will then plug in the RCA's making note to connect them to the right colors. If the RCA's are for subs then this does not matter unless your subs are to play in stereo. Now connect your speaker terminals. If you re planning on bridging the amp, refer to the manual for the amp to see how the manufacturer recommends bridging of the amp. The amp is connected.


Now here is a good method for turning it on for the first time. Pull the RCA's back out of the amp. Turn the head unit off. Put the main fuse in to the amp. Check the amp now. The power LED should not be on. If it is, something is wrong. Stop and figure out what it is before going on. If it is off, go turn the head unit on. Now the power led should turn on. If it did not, then stop and figure out why. It may be a bad connection somewhere. If you have a meter, measure the voltage at the amp terminals. It should be 12V between positive and ground with the car off. If it is not then check the fuse. If it is blown then there is a short in the wiring somewhere. Check to see if the power wire is pinched somewhere. If the fuse is still good then check that the ground is good. You may need to relocate the ground wire if you chose a bad spot. If you have 12V on the amp terminals, then measure between the ground wire and the "REM" wire. If that is 12V also, then the amp may be the cause of the problem. If it does not read 12V, then check the wiring going back to the head unit. It may also be a good idea to take another measurement right off the head unit between the head unit ground and the "REM" wire. If you do not get 12V at the head unit, the head unit may be bad. If you do get 12V at the head unit but not back at the amp, there is a loose connection somewhere. Check the wiring. If the amps power LED turns on then proceed. Turn the gain on the amp all the way down and adjust any filters of crossover points on both the amp and the head unit according to the type of speakers are being powered by the amp. Turn the volume down. Plug in the RCA's Did you hear the speakers "pop". This is good thing. Now turn the head unit volume up a little bit. Is there sound coming out of the speakers? If yes then you have done a good job so far. If no then there is a problem with the speaker wiring. If you can, use a meter to check the speaker terminals on the amp. Remember this is now AC voltage not DC! Do you read voltage? If yes, then you have one of 2 things wrong. It is either blown speakers or it is the wiring going from the amp to the speakers. Check connections. If you do not read any voltage, pull out an RCA and take a reading between the pin and the shield. Now do you read anything? If yes then the problems is with the amplifier. If you do not read anything, go back up to the head unit and take another measurement off of where the RCA connects to on the head unit. Now do you read anything? If yes then the problem is with the RCA being bad. Replace them. If you do not get any voltage, the head unit is the problem. At this point you either have a working amplifier, or you do not but know where your problem is.


I know I better cover this and I know everyone has their own method and reasons for doing it that way. But if you are reading this, then you probably do not know how to do this the right way, yet. This is my way of doing it. I know other will disagree and many more will agree. So that is my disclaimer.

Anyway, first what you should do is turn the gain on the amplifier all the way down. Now raise the head unit volume up all the way and turn up any of the other things you will most likely play with to the highest settings you will ever turn them to (bass boost, bass or treble levels) Now turn up the gain on the amp until you just start to hear distortion coming out of the speakers. Back the gain up just a bit now. That is it! I like this method because now when you are in your car and playing with your head unit, no matter how high you turn up the volume, the speakers will not get any distortion. So you minimize the risk of damaging them.

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